The present invention relates in general to pollution abatement apparatus and, in particular, to contaminant recovery systems for removing and/or recovering contaminant materials from the surface of a body of water.
Only recently has there been an overwhelming realization for the importance of protecting various elements of the earth's environment. In the area of water pollution, for example, society has only started to pay the price for years of careless, indiscriminate pollution of our oceans, rivers and lakes. Industrial wastes and refuse, public sanitation wastes, and mammoth oil spills are only some of the sources of pollution responsible for the virtual destruction of many of our bodies of water. One recent oil spill, for example, responsible for the dumping of millions of gallons of unrefined crude oil into the ocean, attested to the severity of our pollution problems in the form of marred beaches, wildlife destruction, and millions of dollars expended merely to trace the direction of the spill and determine its environmental impact. The overall damaging effects must be realized to include the virtual loss of extremely valuable and expensive resource material itself which could not and has not been recovered for reuse and/or reclamation.
It thus becomes apparent that there exists at present an overwhelming need for systems, apparatus, and the like which make possible the recovery of contaminant material from a myriad of bodies of water in order to prevent the destructive consequences now being encountered. These systems at the same time must be capable of recovering and reclaiming the often valuable resource causing the pollution itself.
Several relatively recent inventions have been directed to just these purposes. Some of these devices, for example, are directed primarily to the separating of oil and solids from water. While these are necessary elements for any attempt to recover the lost contaminant, for the most part, these inventions fail to solve the problem encountered with actually recovering the contaminant from the body of water before separation is attempted.
Other inventions have ranged from the utilization of flexible shields within a boat hull to act as a buffer in case of collision so as to protect an oil cargo; to vacuum inventions in which contaminant material is sucked into a vacuum hose suspended just below the surface of the water to fill a tank. With such a device the oil and water are sucked in together and, if given enough time, separate by gravity, at which time the water can be drained from the bottom of the tank and the oil reused.
In one invention, oil is removed from the surface of water by applying a mixture of wax and a volatile inflammable substance. The resulting mixture is ignited, the wax fuses into a solidified mass and is then picked up. Such an invention is embodied in U.S. Pat. No. 3,785,972. In U.S. Pat. No. 3,785,496, a carbohydrate fatty acid ester in powder, fibrous, or granular form, is applied to spilled oil on water. After picking the absorbent material back up, much of the oil is claimed to be recovered.
Several types of skimming devices have been utilized for the recovery and reclammation of contaminants such as oil. One type of oil skimming device, referred to as a drum type skimmer utilizes a rotating drum or cylinder covered with an oil absorbent material to absorb the oil from the oil and water mixture. The surfaces are generally not wetted by water but instead only by oil. The oil is squeezed or scraped off the surface of the drum by a knife blade or by rollers and then segregated from the water. It should be noted that the effectiveness of this type of skimmer is substantially small due to the substantial inefficiency utilized in skimming and withdrawing the oil from the saturated drum.
Another type of oil skimming device utilizes an oil absorbent surface on a continuous belt to absorb the oil from an oil and water mixture. In a manner equivalent to the drum type skimmer, this belt type skimmer carries the oil to the top of the belt mechanism where a blade or similar piece of equipment squeezes the oil from the belt before recycling. The belt is supported normally on two drums: one to submerge the belt in the oil and water mixture, and the other out of the mixture where the removal of the oil takes place. Besides encountering the inefficient removal problems discussed previously with the drum type oil skimmer, such a belt type oil skimming device is generally limited to calm waters or where oil films are of considerable thickness.
Another type of apparatus removes a surface layer of low density from a body of liquid of higher density. This Weir type of skimming device comprises a flexible pipe or pipes surrounded by a layer of buoyant material in an outer sheath so that the flexible pipes float on the surface of the body of liquid. A number of suction nozzles connected to the flexible pipes, a filter for separating the surface liquid from the liquid of the body and a method for discharging the separated water back into the main body of water are all incorporated into the apparatus. In operation, the pipeline is laid on the surface of the sea so that it surrounds the patch of oil which is to be removed. The suction nozzles dip into the surface layer and the contaminant and a certain amount of sea water are sucked into the piping and carried into a ship where it is forced to a filtering apparatus to separate the oil from the water.
The problems with existing contaminant recovery systems include their inability to accommodate all the variations that can occur with regards to (1) the type of contaminant being recovered, (2) the characteristics of the body of water from which the contaminant is being recovered, and (3) the temperatures of and reactions by the water and the contaminant to one another. For example, while some recovery devices work relatively well in calm waters, these devices have little, if any, effectiveness with turbulent or rolling seas which often complicate the recovery process. Further, all contaminants are not in the same material form. For example, three different types of petroleum contaminants, sweet, sour, and asphaltic, all provide different recovery problems for a skimming or recovery system. Asphaltic oil on the surface of substantially cold water, virtually hardens into an asphalt-like material which needs to be removed more like a solid than a liquid. Additionally, extremes in temperature of any body of water causes a contaminant located thereon to possess different and sometimes peculiar characteristics which cannot often be handled by the conventional skimming apparatus.
For the most part, the conventional skimming, vacuum, or other type of recovery devices require substantial machinery and investment, and are often cumbersome and difficult to deploy and control. Additives which break down the petroleum substance might offer a viable alternative to assist the environment but at the same time they destroy the resource that could be recovered. Various types of barrier restraints which merely surround the contaminant to keep it from spreading, again, protect the environment while doing little in the way of recovering a substantially valuable resource.
It is thus an object of the present invention to provide a system for effectively removing from the surface of a body of water petroleum and/or many other types of undesirable contaminants including vegetation or refuse, while at the same time recovering the contaminant in its original form for reuse or reprocessing.
It is further an object of the present invention to be flexible for use with many different types of contaminants in several types of bodies of water at varying temperatures.
Additionally, it is an object of the present invention to improve the recovery rate and efficiency with which the contaminant is recovered while at the same time being relatively easy to deploy and control.
Further, it is an object of the present invention to provide a system for effectively recovering the contaminant at a substantially reduced cost and with a minimum of manpower.
These and other objects of the invention will become apparent in light of the present specification.